Hi all,
Anyone know what are some methods to repairing damaged threads on a flywheel? I tried to install my flywheel puller and I could not get it to grab the 1st thread. Inspection found the threads pretty buggered up. I do know the threads are left handed. I can't get it started in the threads and I can see that the 1st threads are pushed in in some areas. Is there a tool that can fix threads in flywheels?
I don't have spark.
The bike came with no coil. Bought a new one, cleaned the mounting area, hooked up the black wire to the coil wire. laid the plug on the motor and kicked it a few times in the pitch dark. nothin.. Looks pretty clean inside looking through the flywheel cutouts. Gotta get it off to check..

Thanks

If you are desperate and the threads are damaged badly, I would take a die grinder or Dremel tool with a 1/8” carbide bit and very, very carefully remove the top of the threads that are damaged. Once the portions of tge damaged threads are removed, you should be able to get the puller started. If you aren’t sure what I’m talking about or are not comfortable with the process, don’t try it.

That is a bit drastic for me at the moment..but it may come down to something like that...It seems someone had tried to get it off and was kinda heavy handed attempting to remove it. I will see if I can get a pick or something in there to chase the threads, There is some rust and crud in there that isn't helping. Any alternative ways of pulling on the flywheel other that using the standard puller tool?

Thanks for the advise, I will think about that.

Yep i'd agree with bosco659 & try to relieve the threads at the start. I've got one puller that i've had forever & it's quite long/deep so i've shrtened it once or twice to get good threads from the start. But i see i ground a bit of a short groove in it so must've been trying to force through the faulty threads at the start of one of mine. That trick works to a point so long as it doesn't try to change the threads all the way in. Looks like the end of the crank's had a severe beating at some stage.

Also a reason to buy a quality puller. I misplaced my old K&N puller so bought a cheap one on ebay. Flywheel was really stuck and puller sort of "stripped" and damaged the flywheel in the process.

Bought a Motion Pro puller for like $3 more than the cheap one and was able to eventually get it threaded in to the flywheel and surprisingly the Motion Pro pulled it right off no problem. I ended up replacing that flywheel but I'll never use a cheap puller again.

Once the nut and washer are removed with a sharp angled mini pick and good lighting you should be able to drag the pick across some of the damaged threads cleaning them up enough to get the puller started. Many people don't understand that you have to have the puller on several threads counterclockwise ( this is one of the times - that I use a crescent wrench ) before you hit it with the impact gun. Maybe as much as 6 - 7 threads deep.

Persevere because it is just the greatest feeling when you win..........

I won't attempt to use the puller unless all the LH threads are engaged by threading the puller housing all the way in. This can take some time on a neglected flywheel with corroded threads... but a little time up front is well spent considering the alternative.

I noticed the crank too. Even the corners of the nut look messed up. Maybe the wrong sized socket? Poor bike. Hopefully it will get some TLC from its new owner!

important to remove both washers to get the puller fully home using all the threads & have the puller bolt backed out otherwise it can hit the crank before fully home then that's when threads get pulled. Its a very fine 27mm left hand thread.